Bus driver H Gangappa (42), who was among the injured, succumbed to his injuries while undergoing treatment at a hospital in Bengaluru at around 5 AM, Penukonda Circle Inspector Rajender Yadav said.

Earlier, 15 people, mostly college students, were killed and 35 others got injured when the bus in which they were travelling fell into a dug up area adjoining a hilly road near Penukonda in Anantapur on January 7.

Among the 15 deceased were 10 college students, including a girl, a forest guard and some other passengers, police had earlier said.

At least 30 others are still undergoing treatment at different hospitals in Bengaluru and Anantapur, the police officer said.

Police had registered a case of negligence and under other relevant sections of IPC in connection with the mishap and had taken up investigation on "negligence" of different departments, the inspector said.

Over 50 passengers were travelling in the Andhra Pradesh State Road Transport Corporation (APSRTC) bus which was going to Penukonda from Madakasira.

A large area was dug up on one side of the road where the bus rolled down when its driver apparently tried to overtake an autorickshaw, police had earlier said.